I could retry you could retry she could retry we could retry you could retry they could retry
V-ing form
I could be retrying you could be retrying she could be retrying we could be retrying you could be retrying they could be retrying
Perfect
I could have retried you could have retried she could have retried we could have retried you could have retried they could have retried
V-ing perfect
I could have been retrying you could have been retrying she could have been retrying we could have been retrying you could have been retrying they could have been retrying
Negation
Simple form
I couldn't retry you couldn't retry she couldn't retry we couldn't retry you couldn't retry they couldn't retry
V-ing form
I couldn't be retrying you couldn't be retrying she couldn't be retrying we couldn't be retrying you couldn't be retrying they couldn't be retrying
Perfect
I couldn't have retried you couldn't have retried she couldn't have retried we couldn't have retried you couldn't have retried they couldn't have retried
V-ing perfect
I couldn't have been retrying you couldn't have been retrying she couldn't have been retrying we couldn't have been retrying you couldn't have been retrying they couldn't have been retrying
Interrogative form
Simple form
could I retry? could you retry? could she retry? could we retry? could you retry? could they retry?
V-ing form
could I be retrying? could you be retrying? could she be retrying? could we be retrying? could you be retrying? could they be retrying?
Perfect
could I have retried? could you have retried? could she have retried? could we have retried? could you have retried? could they have retried?
V-ing perfect
could I have been retrying? could you have been retrying? could she have been retrying? could we have been retrying? could you have been retrying? could they have been retrying?
Interro-negative form
Simple form
couldn't I retry? couldn't you retry? couldn't she retry? couldn't we retry? couldn't you retry? couldn't they retry?
V-ing form
couldn't I be retrying? couldn't you be retrying? couldn't she be retrying? couldn't we be retrying? couldn't you be retrying? couldn't they be retrying?
Perfect
couldn't I have retried? couldn't you have retried? couldn't she have retried? couldn't we have retried? couldn't you have retried? couldn't they have retried?
V-ing perfect
couldn't I have been retrying? couldn't you have been retrying? couldn't she have been retrying? couldn't we have been retrying? couldn't you have been retrying? couldn't they have been retrying?